Treating green food



K. SCHMIDT TREATING GREEN FOOD Filed May 2, 1928 Feb. 26, 1929.

Patented Feb. 26, 1929.

UNITED STATES PATENT OFFICE.

Application Med lay 2, 1828, Serial lo.

My invention refers to green food for cattle, sheep etc. and more especially to means whereby such green food can be preserved and its contents of albuminous matter protected against losses by decomposition.

In recent times investigators in several countries, including the United States, have tried to devise means for preserving green food (including grass etc.) in silos with a view to preserving its high contents of albuminous matter. For experience has shown that fresh food stuffs containing albumen have a very favourable infiuence on the health conditions of the animals and more especially on the` quantity and percentage of fatty matter of the milk produced by them. Hitherto the preservation of green food has been effected in several ways. One of the most widely knownv methods is the method of fermentation at elevated temperature, according to which the plantcells are killedby rapid heating to v50" C. In order to attain this temperature, the material is heated either by respiration or by subjecting same to the action of electric current or by the introduction of hot gases. Heating by intramolecular respiration results in a artial destruction of the nutritive value.

eating by means of electric current or hot gases entails considerable expense for the cost of electrical ener y and of-heating material, respectively. or all these purposes the green food must be stored in the silos in dried or rather in withered condition, for moist material will reatly endanger the storage in the silos. oreover the food must in most cases be chopped before being stored and must then be compressed by stamping and pressing. Both these processes further require very long periods of storage in the silo.

Another method which differs fundamen tally from those above described, is carried through by fermentation in the cold, which requires very strong pressure in order to remove the air from the green foodfin the silo inasmuch as the oxygen of the air favours the growth of the bacteria, which are the principal cause of the decomposition of the nutritive matter and of the formation of obnoxious acids, such as butyric and acetic acid.

It has also been su gested to add tothe green food cultures of actic bacteria in order to facilitate and expedite the fermentation in the cold. However, such an addition is objectionable inasmuch as the farmer would be required to increase the parent cultures by circumstantial processes in order to have at mm, mi 1n oei-many :una as, ma.

his disposition suicient quantities of inoculation ymph. The mechanical presses hithcrto used do not allow obtaining ressures above 500 kgs. per square meter, which is not sufficient to remove the air quickly enough. In. consequence thereof pressure must be applied during several weeks whereby higher temperatures and undesirable fermentation, resulting in the decomposition of the nutritive matter, will occur in the silo.

All these difficulties and deficiencies, more especially the losses in substance and nutritive matter, can be avoided accor to the present invention, if the green food, either in chopped or nonchopped condition, is laced in asilo or other suitable container a apted to be airtightly closed, a movable cover, for instance a metal cover or a cover made of suitably treated wood, being placed on top of the green food in the container, and means being provided for ensurin an air-tight fit between the circumferential edge of the cover and the wall of the silo. The air and other gases are then evacuated from the container and from the material stored by suction. While this is being effected, the atmos heric pressure will act on the cover and wi compress the material stored in the silo, while at the same time the moisture in excess contained in the material is removed together with the air and other gases.

The d ee of evacuation t0 be used in each individu air-tight packing wall of the silo. I have found that favourable results can be obtained if the circumferential portion of the cover is packed by means onto the marginal against the wall of t case delpends upon the ofetween the cover anti the own to '30 centimeters mercury column lcan be attained veryquickly even if large quantities of een food (above 5000 kgs.) are treated. it vacuum as specified above sui to strongly com re the material, a pr v of about 4000 per square meter bein' obtained, and the material thus treated-'iwibe subjected to fermentation in the'c'old'v without any further treatment. If "air suction pumps of higher efficiency are used, a higher vacuum will be obtainable.

In the drawings aixed to this specification and forming part thereof means embodyi my invention are illustrated dia ammatica ly in vertical section by way o example.

In the drawings ,a is a cylindrical container (silo) which may be made of metal, concrete, brickwork, wood or some other suitable material rendered impervious to air and other gases by impregnation, lining' or tho like. b is the cover made of metal, wood, armoured concrete or some other suitable material, this cover being shaped to fit in t-lie silo, so as to be axially movable therein. 0 isa packing ring made of vfelt or sonic other suitable packing material', and d isa metalv ring of angular cross sectionixed to thc cover by means of screw bolts e and serving to hold the felt ring c down on'tlie cover and to press same against the wall of the silo a. f is a tubular connection piovided'-\vith a cockA g andvv fitted in a central holeoiI they cover b. 7L is a pressure-proof flexible tubing or hose, mounted with one end on the connectingpiece f, its outerend being connected to a rotaryy suction pump i, the construction of which-need vnot be described as any powerful suction vpumppmay be used for this purpose. e

le is an" annular layer of loain, clay or soiue other plastic ma-terial arranged on top of the rings cydvand forced by pressure against the top of the marginal portion of cover b and agains-t the inner wallof the container a so as toclo'sely applyitself against these. surfaces; This annulus will eflicieiitly seal any gap left between the cover b and conl tainer a and will descend with the .cover b or may be'arranged thereon onlyafter this cover has attained its lowermost position.

In the operation of this arrangement the cover b is first removed fiom 'the container 'and the material to be treated is illed'fin,

whereupon the cover is placed in the container on top of the material and is forced down by pressure so far that the'felt iing c applies itself against the inner wallk of the container. The suction pump is now set operating and by sucking the air and moisture from the interior of the container and from the inaterial stored therein will create a vacuum in the container below the' cover, whereby this latter will 'be forced down into the container under the action of the atmospheric pressure, compressing the material in the container.

As a Vresult of a very great number of tests I have'found that if a container or silo having a diameter of 4? meters and being 5,5 meters high, was filled with green food up tothe top and the cover was placed in position and the suction pump started, the material was compressed after the lapse of one hour substantially to the' extent of being ready for cold fermentation, the distance between the cover and the to edge of the silo after one hours pumping eing about 2,5 meters.

In the manner aforesaid grass, clover, lucern, maize and turnip tops have been treated vwith the greatest success.

I have furtherfound that I can improve` and to cnterthe container, distributing in the green food contained therein. ,I have found that small quantities of carbon disulfide amounting to about 15 kgs.- per 50,000 kgs. green food 'suice fully to attain the desired result. By experiments carried out with guinea-pigs and cows it has been shown that the carbon disulfide treatment is entirely animals fed with such food.

Sheep weighing about 45kgs. live weight, on, being fed during four weeks with green food treated iii accordance with this invention, showed an increase inV weight up to 5 rgs. (ll per cent), each animal being fed daily with i kgs. lucern and 1 kg. straw.

The chemical analysis of lucern treated in accordance with this invention gave the following results:

innoxious, working no harm whatever to the iExtracE Crude Purs t Y ma ter free protein albumen from nitrogen Raw produca 2o. 6% l11.3%J 41.8% Treated product 20. 6% l 8.4% 30. 1%

The acidanalysis showed the following results:

Com- Free Ammo- Lactic Butyrlc bined acetic nia nitroacld acid acid nacc gen o. 94% o. 56% a 27% y(1.058%

Ihe smell. of the treated food was that ofv well pickled cucumbers. Y

The invention offers the following advantags, as compared with the methodsv hitherto use e While the electric treatment of 50,000 kgs. green food requires 50-90 hours, the vacuum treatment according to this inventionrequires only 8 hours. A great savingl of labour and electrical energy is obtained, the electrical treatment requiring from 2.6 to 6 kilowatthours, the vacuum treatment only 0.2 kilowatt hours per 100 kgs. Time and labour are furth-erlsaved for the chopping, most of the green food-being operated on in non-chopped condition. No decomposition of albuminousmatter and more especially of vitamines by selfheating is experienced. In the hot fermentation process, if a tem erature of 50 C. shall not be overstepped, t e fermentation process must be kept under careful control inasmuch as the heating tendency of the different kinds of green food and even of the same kinds will differ greatly according to ripeness and moisture. In the practical operation of the hot fermentation rocess the temperature frequently rises above 50 C., whereby valuable nutritive matter is decomposed and the digestibility of the food is greatly reduced. Owing to the very high compression which may attain almost 10,000 kgs. per square meter, as compared with only 500 kgs., when emplo ing mechanical presses, the air is remove very quickly and the food is compressed very strongly, thereby producing a reduction of temperature which does not allow any undesirable fermentation to arise and prevents the resouring when the compressed material is withdrawn from the silo. The air-tightly closing cover prevents air from entering the silo, so that the material can be consumed up to the topmost layers. In the fermentation rocess the analysis of the gas contained in t 1e compressed material shows already after a short treatment great quantities (80-90 per cent) of carbonio acid, however, the percentage is subject to material fiuctuations during the first two weeks and the same is true of the percentage of oxygen, which does not, however, attain more than 15 per cent. However, this increase of energy is known to be accompanied by the decomposition of nutritive matter, more escially the easily digestible albumen and car hydrates, and it is therefore important that this decomposition be shortened as much as possible. This is effected by treating the material in accordance with the present invention, which also provides for automatic removal of rain and dew moisture and of the plant juices in excess, so that the farmer is independent of the weather.

Various changes may be made in the details disclosed in the foregoing specification without departing from the invention or sacrificing the advantages thereof.

claim 1. The process of preserving green food comprisin removing from the food part of the air an other gases and moisture by evacuation, at the same time acting on said food with pressure and introducing a bactericidal gas.

2. The process of preserving green food comprisin removing from the food part of the air anv other gases and moisture by evacuation, at the same time acting on said food with pressure and introducing carbon disulfide va our.

3. e process of preservin green food comprising simultaneously su jecting the food to compression and evacuation of a ortion of the air, gases and moisture contalned therein.

In testimony whereof I aiix m signature.

KARL S HMIDT. 

